Data modulation method for IEEE 802.11 devices to generate low frequency signals

Abstract

A data modulation method with low frequency signals, encapsulating a plurality of data along with an identifier corresponding to one or multiple LR receivers, and a given preamble into their associated fields to form a LR frame by means of a formatter. The preamble of the LR frame prepares the LR receiver for the reception of the receiver ID and data. An encoding stage whereby a line code generates a plurality of coded data from an LR frame. The transmission of the coded data using ASK modulation through an encoder, rules the transmission of a frame burst emulating the transmission of a modulated low frequency carrier signal. The frame burst is composed of frames compliant with any standard defined by the IEEE 802.11 Working Group or IEEE 802.15 Working Group.

Description

FIELD OF THE INVENTION[0001]The present invention can be classified within the field of wireless communications. More precisely, this invention closely relates to IEEE 802.11-based wireless local area network (WLAN) technologies, and IEEE 802.15-based wireless personal area network (WPAN) technologies.BACKGROUND OF THE INVENTION[0002]In the document Mishra, N.; Chebrolu, K.; Raman, B.; Pathak, A., “Wake-on-WLAN”, in Proceedings of WWW Conference 2006, authors propose using “sleeping” WLAN stations featuring a low-power sensor to monitor the stations' working channel. Upon energy detection in such channel, the sensor is in charge of waking up the main WLAN transceiver. Although this approach has the advantage of not requiring a custom transmitter, the number of false positives detected by the sensor is too high, even when the system operates in a lightly loaded ISM (Industrial, Science & Medical) channel.[0003]The same authors tried to overcome this issue by incorporating address pat...

AI Technical Summary

Benefits of technology

Enables efficient, low-power communication with feature-limited wireless receivers, reducing energy consumption and interference, and maintaining compatibility with off-the-shelf devices, while minimizing hardware changes.

Problems solved by technology

Unfortunately, for communications with purposes other than Wake-up, the data-rate of this strategy is too low (the wake-up signal can last up to 1 second).

In addition, due to the long silence periods (˜20 ms), this system is still prone to interferences.

However, although more resilient to interferences, this approach is still slow, and thus inappropriate for long data transmissions.

Furthermore, the current consumption of its associated Wake-up Receiver design is in the milliAmper (mA) order.

This is simply unacceptable for Wake-up Radio systems, where receivers should not employ more than 10 μW.

Again, surrounding transmissions, even from a different standards such as IEEE 802.15.4, may invalidate an ongoing Wake-up procedure.

This approach requires severe hardware and software modifications in standard-compliant devices.

Furthermore, it is limited to IEEE 802.11 transmissions based on OFDM, which allow for shorter communication range than the ones based on DSSS (Direct Sequence Spread Spectrum).

However, such implementations do not consider or implement a low frequency, low-rate signal using standard-compliant IEEE 802.11 / 802.15 frames.

In fact, even if some of the previous solutions could be used for similar purposes, they would be either inefficient or require intensive hardware modifications.

These two issues strongly limit their potential reproducibility and applicability.

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